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Corrosion prevention strategies for electric motors and generators

Read Time: 3 mins

Generators and electric motors play a crucial role in various industries, providing power generation and converting electrical energy into mechanical energy. However, these assets are often exposed to harsh environments, increasing the risk of rust and corrosion, which can lead to operational interruptions and shorter service life. To address this issue, corrosion prevention becomes a valuable and vital effort. Cortec® Corporation offers the following tips to help mitigate corrosion in generator and motor cores, copper stator cooling systems, generator oil systems, and external surfaces:

1. Corrosion Prevention in Generator and Motor Cores:
– Qualified maintenance engineers can apply ElectriCorr™ VpCI®-239 by spraying smaller cores or fogging larger cores when the equipment is powered off. This protective fluid not only acts as a cleaner but also forms a thin corrosion inhibiting film when dried, providing protection against aggressive industrial, marine, or tropical conditions.
– To further protect accessible metal surfaces within the generator housings, a VpCI®-308 Pouch can be added. This pouch releases Vapor phase Corrosion Inhibitors (VpCI®) that form a protective molecular layer on metal surfaces, inhibiting corrosion on both ferrous and yellow metals.

2. Removing and Reducing Corrosion in Copper Stator Cooling Systems:
– Large water-cooled generators face the risk of corrosion on copper components, particularly inside hollow copper conductors where cooling water flows. Cortec® recommends using VpCI®-422 or VpCI®-426 to remove copper oxides by adding them to the system and allowing them to dwell or circulate for two hours or as needed.
– After rust removal, the cooling water tubes should be rinsed and neutralized with a VpCI®-41x Series cleaner. Then, they should be rinsed with VpCI®-648 treated water, an additive designed for corrosion protection of ferrous metals and copper in deionized or reverse osmosis water.

3. Layup of Generator Oil Systems:
– Adding M-535 to generator oil systems during layup provides corrosion protection. This additive contains Vapor phase Corrosion Inhibitors (VpCI®) that protect metal surfaces in direct contact with the treated oil, as well as metal surfaces in the headspace above the fluid level. It is also non-corrosive to copper.

4. Protecting External Surfaces and Junction Boxes:
– For generators exposed to outdoor weather conditions, Cortec® recommends applying VpCI®-391 (a hazy, non-tacky water-based removable coating) or EcoShield® VpCI®-386 (a clear permanent water-based coating with UV resistance) over painted or unpainted machine surfaces to enhance external protection.
– Junction boxes on generators and motors can be protected by installing a VpCI®-101 Device, a self-adhesive foam infused with Vapor phase Corrosion Inhibitors (VpCI®) that condition the enclosure with protective vapors.

By implementing these corrosion prevention measures, maintenance personnel and operators can extend the service life of generators and motors, ensuring immediate readiness for emergency backup. For more specific advice on preventing corrosion in electric generators and motors, it is recommended to contact Cortec® Corporation.

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